<!DOCTYPE html>
<html>
<head>
	<title></title>
	<script type="text/javascript">
		
		// 循环语句
		// i++ 累加  i += 1
		for(var i = 0; i < 5; i++){

			console.log(i)
		}

		var index = 0
		while (index < 5){
			
			console.log(index)
			index += 1
		}

	</script>
</head>
<body>

</body>
</html>